Muffler.



D. F. LEARY MUFFLER.

APPLICATION FILED MAR-6,1913. RENEWED 001'. 19.2915.

1,1 9 1 ,902, Patented July 18, 1916.

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UNITED STATES PATENT OFFICE.

DENNIS F. LEARY, OF CHELSEA. MASSACHUSETTS.-

MUFFLER.

Specification of Letters Patent.

Patented July 18, 1916.

. Application filed March 6, 1913, Serial No. 752,286. Renewed October 19, 1915. Serial No. 56,797.

To all whom it may concern:

Be it known that I, DENNIS FRANCIS LEARY, a citizen of the United States, and a resident of the city of Chelsea, in the county of Suffolk and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Mufllers, of which the following is a full and exact description.

My invention relates to means for mufiling the exhaust from an internal combustion engine, and for other mechanisms where a sudden discharge of gas or steam produces objectionable noise.

To this end, my invention comprises a casing adapted to tangentially receive the exhaust, and containing a fan disposed to be set in motion by the force of the exhaust and to eject the same in a substantially uniform stream or streams.

Referring to the drawings forming part of this specification, Figure 1 is a central longitudinal section of a muiller embodying my improvements. Fig. 2 is a cross section on the line XX in Fig. 1. Fig. 3 is a cross section on the line YY in Fig. 1. Fig. 4: is a perspective view of the mufiier on a smaller scale.

The casing 1 of the mufiler is preferably cylindrical, with heads 2 carrying bearings 3 for the axially supported shaft 4. At the midlength of said shaft is a fan 5 fixed thereon, and revolving between partitions 6 which compose a chamber into which the exhaust is tangentially discharged through a conduit7. Through each of said partitions is an opening 9 at a mint substantially opposite to the intake rom said conduit; and midway between each of said. partitions and a head 2 is another partition 10 having an opening 11 diametrically opposite to the openings 9. Tangentially leading from the outermost chambers thus formed are the discharge conduits 12, opening therefrom diametrically opposite to said openings 11. Hence, after the exhaust enters the firstnamed chamber, it passes to the opposite side thereof and then divides right and left to flow through said openings 9; thence to the opposite sides of the chambers 13 and out through the openings 11, and finally once more across in the chambers 14, to the dischargeconduits 12. In this manner, the flow of the exhaust is so interrupted as to greatly aid in checking its force and rendering its travel a more nearly continuous flow. The greatest element for this latter purpose, however, is the fan 5, which acts by its received motion to force the gases out through the openings 11 and along their circuitous passages to their final discharge. In other words, since the exhaust of an engine, whether hydrocarbon or steam, occurs in a succession of violent blasts, and each blast meets the fan-vanes with an impact which whirls the fan with great energy; and since the intervals of time between these blasts is insufficient to allow any appreciable slowing down on the part of the fan, the latter acts during such intervals as a fan-blower to impel the gases along their tortuous way and so preserve such a continuity of flow as to allow no such interruptions as would cause any appreciable noise.

By locating the fan at the midlength of the casing and dividing the escape therefrom into two streams, the energy of each is correspondingly diminished, so that by the combination of a divided flow, a tortuous channel, and a momentum driven fanblower, a mufller is produced of maximum eiliciency, and yet of minimum back-pressure on the engine.

If desired, a pulley 15 may be mounted upon a projecting end of the shaft r, and the latter and fans supported thereby may be rotated by power from the engine shaft. for the further reduction of back pressure. Moreover, propeller blades 18 may be mounted on said shaft in certain of the. compartments, as shown in Fig. 1, so that the forcible rotation of the shaft may be utilized for the more rapid expulsion of the exhaust and the still further diminution of back pressure.

Although I have illustrated the intake 7 as delivering the exhaust at a lowermost part of the mufiier .drum, 1 donot restrict myself thereto, inasmuch as it may enter a higher point, and the discharge pipe or pipes 12 may also be changed from their illustrated positions.

What I claim as my invention and for which I .desire Letters Patent is as follows, to wit;

A mufller comprising an elongated casing, several transversely disposed partitions therein formingcompartments, one of which is central, each partition having an opening through it staggered relative to the openings in adjacent partitions, means for delivering exhaust to the central compartment, a fan located in said central compartment adapted to be rotated by said'exhaust, and a transversely disposed discharge for the exhaust at eachend of said casing.

In testimony that I claim the foregoing invention, I have hereunto set my hand this 20th day of February, 1913.

DENNIS F. LEARY.

Witnesses:

A. BLEPHAM,. JOSEPH W. Downs. 

